김지희 교수

Piezostacks are capable of producing very large forces, but they provide only limited displacements. Thus, the displacement amplification mechanism is necessary to make those actuators more efficient and useful. For this purpose, a two-bridge-type flexure hinge mechanisms in series in a three-dimensional structure is proposed in this study. To show the validity of the proposed mechanism, the kinematic analysis is carried out by a matrix method and by a finite element method, and then the amplifi

Our results suggest that implantation of barbed thread induces strong anchorage to skin tissue. Quantitative analysis of collagen and its downstream signaling molecule TGF-β supports the long-term durability of the thread. Therefore, the authors expect potential beneficial effect for rejuvenation on its clinical application.

The residue of ground coffee obtained after the brewing process (spent coffee) still contains various functional components with high antioxidant capacity and health benefits, but no attempts have been made to use it as a resource to produce value-added food ingredients. This study evaluates the antioxidant activity of ethanol or hot water extracts from the residues of coffee after brewing. An extraction experiment was carried out using the conventional solid-liquid methods, including ethanol an

Our study suggests that topical application of a combination vitamins C, E, and ferulic acid antioxidant formula may be effective as an adjuvant option in QSNY lasers.

Protein tyrosine kinase 7 (PTK7) is a catalytically inactive receptor tyrosine kinase that is also known as colon carcinoma kinase-4 (CCK-4). Recent reports have shown that PTK7 plays an important role in carcinogenesis, and it is known to be upregulated in gastric, colon and esophageal cancer, as well as in liposarcoma. However, the role of PTK7 in lung cancer has not been investigated. The aim of the present study was to investigate the expression levels and the role of PTK7 in lung cancer. We

Previous studies described the involvement of extracellular signal-related kinase (ERK) in systemic fibrotic diseases, but the role of ERK in cutaneous scarring is unknown. Although hypoxia drives tissue fibrosis by activating hypoxia-inducible factor-1α (HIF-1α), the specific roles of hypoxia and associated ERK phosphorylation in abnormal fibroblast activity during cutaneous scarring are unclear. Here, we investigated whether pathologic myofibroblast-like keloid fibroblast activity is promoted